SAN ANTONIO >> On a day of rest at the NBA Finals, Tim Duncan had work to do.

Not only was he admittedly awful in Game 2, he had never been so bad on this stage. He shot 3 for 13 from the field for nine points, posting finals career lows in scoring, field goal percentage and field goals made, according to STATS.

The three-time finals MVP made only 11 of 32 shots in Miami and knows he must be better if the San Antonio Spurs are going to win their fifth title in five finals appearances.

“Obviously, they’re contested shots, but they’re the shots I feel I can make,” Duncan said after the Heat’s 103-84 victory Sunday. “So whether it be them or me or whatever it may be, I’m going to get back in the gym tomorrow and hopefully come out with a better stroke,” he said. “But I’m getting the shots I want. I just have to knock them down.”

The teams took Monday off, with the series resuming Tuesday night. The Spurs also will host Game 4 on Thursday and Game 5 on Sunday.

The finals were once as much a part of June as the heat in this city deep in the heart of Texas. San Antonio won four titles in a nine-year span starting in 1999, but hasn’t hosted a game in the NBA’s championship round since the Spurs took a 2-0 lead over LeBron James and Cleveland in 2007.

Here comes James again, needing to win one here — which hasn’t been easy for Miami — and not concerned that the finals’ 2-3-2 format now gives the advantage to the Spurs.

“It doesn’t matter,” he said. “Two best teams in the NBA at this point. Both teams have won and can win on each other’s floor. So it’s not a biggie.”

The Heat are just 3-22 in San Antonio, though they did win this year even while James, Dwyane Wade and Mario Chalmers sat out the late-season meeting.

James had no cause for concern after Game 2, which validated his belief that he can depend on his teammates until he gets rolling, as he did late in the third quarter and well into the fourth.

But a little doubt seemed to creep into the Spurs’ Big Three, unusual for a group that has been there, done that.

The Spurs took home-court advantage away from Miami, but no momentum after the reigning champions took them apart Tuesday.

“Not after tonight. I think they regained that,” Duncan said. “Obviously we were glad to win a game here in Game 1. Our goal was to get two. But they got the one tonight. We get to go back home. We got a game here. We have three at home, so we’re excited about that. But if we play like we did tonight, that’s not going to matter.”

Duncan, Tony Parker and Manu Ginobili have teamed for 99 postseason victories together, second-most in NBA history, and the trio is well aware of how quickly things can change in the playoffs.

They changed really quickly in this series, about the time it took James to turn Tiago Splitter’s dunk attempt into a blocked shot and an instant finals highlight.

“Of course if you look at the result, being 1-1, it’s not bad. But you don’t want to play like this in an NBA Finals,” Ginobili said. “You don’t want to give them that much confidence, and you feeling bad about yourself.”

Parker managed only five baskets in 14 attempts while making five turnovers, and Ginobili had three of the Spurs’ 17 turnovers that led to 19 points Sunday, after the team tied a finals low with four turnovers in a Game 1 victory.

The Spurs, like every other team in the NBA, know there’s no way to beat the Heat with that kind of ball handling.

“We have to play better. Definitely have to play better,” Parker said. “You know, we’re playing the defending champs. They’re a great team. We knew they were going to come in and play with a lot more energy and play harder. That’s what they did tonight.

“So it’s always easy to bounce back after a loss, and now it’s our turn to see how we’re going to handle our loss and how we’re going to respond.”

Big Three against Big Three provided plenty of buildup to the series, and Ginobili said the Spurs stand little chance of winning if their trio plays poorly.

But James, having seen the Heat not have enough when they were largely just he, Wade and Chris Bosh two years ago, insists his current team is deep enough to do big damage even when it doesn’t come from the big names.

“I think the supporting cast is really why both teams are here,” James said. “They’ve been making an impact all year long, and they feel like their supporting cast is better. We feel like our supporting cast is better. It’s who goes out and do it each and every night to help seal wins.”

The Spurs are shooting just 41 percent and averaging 88 points in the series, perhaps lucky to not be down 2-0, and realize they needed to be much sharper when they got back home.

“It’s about getting refocused here, playing a much better game, ending quarters better, and hopefully shooting better,” Duncan said